7 Surprises Hurricane Irene May Have In Store

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Imagine this scenario: A hurricane has made landfall in a nearby
town. You look outside but all you see outside is rain. No
lightning. No thunder. No sign of the apocalypse. Then all of a
sudden there's a big, fat tornado on the horizon.

People usually have days to prepare for a hurricane, but
hurricane-spawned tornadoes (yes, hurricanes can and do spawn
tornadoes) can catch people off guard.
Hurricane Irene might not be a repeat of Hurricane Beulah, a
1967 storm that spawned more than 100 tornadoes across Texas, but
the threat is real with any hurricane that makes landfall.

Hurricanes are basically a big, swirling mass of thunderstorms.
Thunderstorms can spawn tornadoes, and hurricanes are no
exception.But for a hurricane to spawn a tornado, the center of
the storm needs to come a few hundred miles inland. When a
hurricane makes landfall, friction causes winds at different
heights in the storm to change directions, creating the wind
shear needed to produce tornadoes.

Wide, wedge tornadoes are possible, but the twisters are usually
weaker than their Great Plains counterparts, said Eugene McCaul,
an atmospheric scientist at NASA's Marshall Space Flight Center
in Huntsville, Ala.

"You don't tend to see these tall majestic tornadoes in
land-falling hurricanes," McCaul told OurAmazingPlanet. "They
tend to be these low, raggedy things."

Irene looks like it will brush the Carolinas, so a big
hurricane-spawned tornado outbreak isn't likely there. If Irene
makes landfall in Long Island, areas east of the storm could see
some twisters, while New York City would likely see only heavy
rains and winds. Irene could continue north, but
hurricane-spawned tornadoes are rare in New England, McCaul said.

"I would not expect a huge tornado outbreak with this one,"
McCaul said.

Storm surge

Irene's strength has dropped to a Category 2 storm, and should
not strengthen back to a major hurricane, according to the
National Hurricane Center (NHC) (major hurricanes are Category 3
or higher on the Saffir-Simpson
scale of hurricane strength ). But Irene should still pack a
punch, since it has already developed a massive swell of water
that it will carry north.

Irene's swell could spill onto low lying areas. Storm surge, an
abnormal rise in water, occurs when strong winds push water
forward, ahead of a moving storm. Huge waves form on top of the
surge, cresting and pounding the coast.

This could be a problem for Long Island, if those north-blowing
winds, and the surge they push in front of them, hit it head-on.

A major hurricane (Category 3 or higher on the Saffir-Simpson
scale of hurricane strength ) could push more than 30 feet (9
meters) of storm surge into low-lying parts of New York City.
That's a worst-case scenario; current
computer models forecast a small chance of a storm surge of 2
feet (0.6 meters) in the region.

Whopper waves

Storm surge is like a rising tide that doesn't recede. Riding
atop the storm surge are massive waves. The U.S. Navy has
predicted wave heights of around 30 feet (9 m) for the New York
region. The waves will repeatedly crash onto the coast.

Heavy rain

The U.S. National Oceanic and Atmospheric Administration
(NOAA) has forecast around 8 inches (20 centimeters)
of rain for New York City. Other parts of the region could
see up to 15 inches (38 cm).

This past spring was sopping wet, so the ground is already
saturated. The storm surge and heavy rain could bring widespread
flooding across New York and New Jersey. In New York City, subway
stations and sewer flooding could be a problem as the heavy rain
overwhelms the underground tunnels.

Transit trouble

In an attempt to reduce the threat of subway flooding, New York
Gov. Andrew Cuomo said that the entire New York City transit
system will shut down tomorrow (Aug. 27) at noon.Elevated tracks
would also be in danger from high winds.

An
MTA spokesman told the New York Times that they cannot
guarantee the safety of passengers on trains if winds are above
39 mph (63 kph) for a sustained period. Cuomo
added that area bridges will also be closed if wind speeds exceed
60 mph.

Flooding could also be a problem at New York City's coastal
airports. As a precaution, JetBlue has already cancelled 880
flights ahead of Irene.

Whipping winds

Category 1 strength hurricanes have winds of at least 74 mph (119
kph). Hurricane force winds are currently felt up to 90 miles
(145 kilometers) from the eye. If the storm hits Long Island,
tropical storm force winds, or worse, could pound New York City.
Windows could shatter, buildings could sway and debris could
rocket down the streets.

The New York City Office of Emergency Management advises
high-rise dwellers to be prepared to move to the 10th floor or
lower if necessary.